From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DADFF3EB0FF; Tue, 22 Sep 2026 04:29:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790051362; cv=none; b=CXdF7NrdMu4mWElbDphQffHnF+2ygyEsksQd5vqrcCCGBXYsUr1vxCImvoDbmwYawcSAowDYsh1VkN3ZLHP+5ZP9smjOjVzu9DBoOopwdEziUBwniO0lB+vyQXzqgsY7rrwmJfEiFkYi9Ey0e5oyUyD0vbRNntUyZkx6EtLzLnI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790051362; c=relaxed/simple; bh=qFV5K/HugzkNwnsVmrFhjN5KFU6GtvcjXht7j4MSDfc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=V4B+irhnjO0ET45zrEFQNjA6v/LDdGUNtyfwx00fuvHvhldk3kLVCfECfxuCv8eEA2cI2kfiZONAm3rcODI83h2D81hdCPQ/8lVUGzqG3F96l8JoUD5G7ATmY3GAxiAVji5p1kirYg7f1gIRqPRzWs+Z/KI70Zm7BFPveM+ozWk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=o1uX8BUb; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="o1uX8BUb" Received: by smtp.kernel.org (Postfix) with UTF8SMTPSA id 6B3771F000FF; Tue, 22 Sep 2026 04:29:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790051360; bh=ztv4F61HSZ3KwajIQnl3uHBdxxdP/TCiacbWHOmAb5I=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=o1uX8BUbnCHJgtwFBxqVr+fGj++BROg8jaWuCTXLgu8GmkiSQSJ4m9V2Vlsbh+RcO 7pnJr4hKg3xcGqBZ3NeA1ZWdBD9O99t3JvYu6HiBCOGLjTz3659/gIdEshHuCNFRz3 ps0TyJFJI8K0E00/uTlnqjUKZIgLWZrFiJo7LBBQUsgXfDyAsiG/LQzo/twN1agXeL xJMWhEE/Ge418UsjZgPwrSm9COMxeqB0wpg7/2lzS+ZkCQuWB7iLkHUJTBMCffZrev 5sR9SMBnbdPK2R09DOxrjB03ziF+ruJ5BZjTQk4jvFw7LZXGJY3JmQNuX81CUyiVf0 8jM7qsTqi6iyw== Date: Mon, 21 Sep 2026 21:29:19 -0700 From: "Darrick J. Wong" To: Andrey Albershteyn Cc: ebiggers@kernel.org, hch@lst.de, Carlos Maiolino , fsverity@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-xfs@vger.kernel.org, linux-unionfs@vger.kernel.org, linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-btrfs@vger.kernel.org, david@fromorbit.com Subject: Re: [PATCH v16 12/21] xfs: use read ioend for fsverity data verification Message-ID: <20260922042919.GL2705364@frogsfrogsfrogs> References: <20260918111539.1003439-1-aalbersh@kernel.org> <20260918111539.1003439-13-aalbersh@kernel.org> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260918111539.1003439-13-aalbersh@kernel.org> On Fri, Sep 18, 2026 at 01:15:24PM +0200, Andrey Albershteyn wrote: > Use read ioends for fsverity verification. Do not issue fsverity > metadata I/O through the same workqueue due to risk of a deadlock by a > filled workqueue. > > Pass fsverity_info from iomap context down to the ioend as hashtable > lookups are expensive. > > Add a simple helper to check that this is not fsverity metadata but file > data that needs verification. > > Signed-off-by: Andrey Albershteyn Seems fine to me, though I would like to see hch's blessing on this since he's written more of the read ioend workqueue completion code. Reviewed-by: "Darrick J. Wong" --D > --- > fs/xfs/xfs_aops.c | 13 +++++---- > fs/xfs/xfs_file.c | 3 +- > fs/xfs/xfs_fsverity.c | 11 ++++++++ > fs/xfs/xfs_fsverity.h | 14 ++++++++++ > fs/xfs/xfs_ioend.c | 65 +++++++++++++++++++++++++++++++++++++++---- > fs/xfs/xfs_ioend.h | 4 ++- > fs/xfs/xfs_super.c | 15 ++++++++++ > 7 files changed, 112 insertions(+), 13 deletions(-) > > diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c > index 19640e4e3ed1..a36f840884b4 100644 > --- a/fs/xfs/xfs_aops.c > +++ b/fs/xfs/xfs_aops.c > @@ -24,6 +24,7 @@ > #include "xfs_zone_alloc.h" > #include "xfs_rtgroup.h" > #include "xfs_fsverity.h" > +#include > > struct xfs_writepage_ctx { > struct iomap_writepage_ctx ctx; > @@ -611,7 +612,7 @@ xfs_bio_submit_read( > { > xfs_ioend_submit_read(iter->inode, ctx->read_ctx, > ctx->read_ctx_file_offset, > - iomap_ioend_flags(&iter->iomap)); > + iomap_ioend_flags(&iter->iomap), ctx->vi); > ctx->read_ctx = NULL; > } > > @@ -623,11 +624,13 @@ static const struct iomap_read_ops xfs_iomap_read_ops = { > > static inline const struct iomap_read_ops * > xfs_get_iomap_read_ops( > - const struct address_space *mapping) > + const struct address_space *mapping, > + loff_t pos) > { > struct xfs_inode *ip = XFS_I(mapping->host); > > - if (bdev_has_integrity_csum(xfs_inode_buftarg(ip)->bt_bdev)) > + if (bdev_has_integrity_csum(xfs_inode_buftarg(ip)->bt_bdev) || > + xfs_fsverity_is_file_data(ip, pos)) > return &xfs_iomap_read_ops; > return &iomap_bio_read_ops; > } > @@ -639,7 +642,7 @@ xfs_vm_read_folio( > { > struct iomap_read_folio_ctx ctx = { .cur_folio = folio }; > > - ctx.ops = xfs_get_iomap_read_ops(folio->mapping); > + ctx.ops = xfs_get_iomap_read_ops(folio->mapping, folio_pos(folio)); > iomap_read_folio(&xfs_read_iomap_ops, &ctx, NULL); > return 0; > } > @@ -650,7 +653,7 @@ xfs_vm_readahead( > { > struct iomap_read_folio_ctx ctx = { .rac = rac }; > > - ctx.ops = xfs_get_iomap_read_ops(rac->mapping), > + ctx.ops = xfs_get_iomap_read_ops(rac->mapping, readahead_pos(rac)); > iomap_readahead(&xfs_read_iomap_ops, &ctx, NULL); > } > > diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c > index 07abf6e8783f..578ca6fb8292 100644 > --- a/fs/xfs/xfs_file.c > +++ b/fs/xfs/xfs_file.c > @@ -225,7 +225,8 @@ xfs_dio_read_bounce_submit_io( > loff_t file_offset) > { > xfs_ioend_submit_read(iter->inode, bio, file_offset, > - iomap_ioend_flags(&iter->iomap) | IOMAP_IOEND_DIRECT); > + iomap_ioend_flags(&iter->iomap) | IOMAP_IOEND_DIRECT, > + NULL); > } > > static const struct iomap_dio_ops xfs_dio_read_bounce_ops = { > diff --git a/fs/xfs/xfs_fsverity.c b/fs/xfs/xfs_fsverity.c > index e30021c22683..525855fdd30d 100644 > --- a/fs/xfs/xfs_fsverity.c > +++ b/fs/xfs/xfs_fsverity.c > @@ -14,9 +14,20 @@ > #include > #include > > +struct kmem_cache *xfs_fsverity_ioend_cache; > + > loff_t > xfs_fsverity_metadata_offset( > const struct xfs_inode *ip) > { > return round_up(i_size_read(VFS_IC(ip)), XFS_FSVERITY_START_ALIGN); > } > + > +bool > +xfs_fsverity_is_file_data( > + const struct xfs_inode *ip, > + loff_t offset) > +{ > + return fsverity_active(VFS_IC(ip)) && > + offset < xfs_fsverity_metadata_offset(ip); > +} > diff --git a/fs/xfs/xfs_fsverity.h b/fs/xfs/xfs_fsverity.h > index c2ab5af89370..836e3a4eb194 100644 > --- a/fs/xfs/xfs_fsverity.h > +++ b/fs/xfs/xfs_fsverity.h > @@ -6,15 +6,29 @@ > #define __XFS_FSVERITY_H__ > > #include "xfs_platform.h" > +#include > > #ifdef CONFIG_FS_VERITY > loff_t xfs_fsverity_metadata_offset(const struct xfs_inode *ip); > +bool xfs_fsverity_is_file_data(const struct xfs_inode *ip, loff_t offset); > #else > static inline loff_t xfs_fsverity_metadata_offset(const struct xfs_inode *ip) > { > WARN_ON_ONCE(1); > return ULLONG_MAX; > } > +static inline bool xfs_fsverity_is_file_data(const struct xfs_inode *ip, > + loff_t offset) > +{ > + return false; > +} > #endif /* CONFIG_FS_VERITY */ > > +struct xfs_fsverity_ioend { > + struct iomap_ioend *ioend; > + struct work_struct work; > +}; > + > +extern struct kmem_cache *xfs_fsverity_ioend_cache; > + > #endif /* __XFS_FSVERITY_H__ */ > diff --git a/fs/xfs/xfs_ioend.c b/fs/xfs/xfs_ioend.c > index e70be5b86f0b..2f46855b052f 100644 > --- a/fs/xfs/xfs_ioend.c > +++ b/fs/xfs/xfs_ioend.c > @@ -18,7 +18,26 @@ > #include "xfs_ioend.h" > #include "xfs_error.h" > #include "xfs_errortag.h" > +#include "xfs_fsverity.h" > #include > +#include > + > +static void > +xfs_end_fsverity_io_read( > + struct work_struct *work) > +{ > + struct xfs_fsverity_ioend *fsv_ioend = > + container_of(work, struct xfs_fsverity_ioend, work); > + struct iomap_ioend *ioend = fsv_ioend->ioend; > + struct bio *bio = &ioend->io_bio; > + > + kmem_cache_free(xfs_fsverity_ioend_cache, fsv_ioend); > + > + if (!bio->bi_status) > + fsverity_verify_bio(ioend->io_vi, bio); > + > + iomap_finish_ioends(ioend, blk_status_to_errno(bio->bi_status)); > +} > > static void > xfs_dio_bounce_end_io( > @@ -93,12 +112,14 @@ xfs_read_bounce_and_resubmit( > > static void > xfs_end_io_read( > - struct bio *bio) > + struct bio *bio) > { > - struct iomap_ioend *ioend = iomap_ioend_from_bio(bio); > - struct xfs_inode *ip = XFS_I(ioend->io_inode); > - struct xfs_mount *mp = ip->i_mount; > - int error = blk_status_to_errno(bio->bi_status); > + struct iomap_ioend *ioend = iomap_ioend_from_bio(bio); > + struct xfs_inode *ip = XFS_I(ioend->io_inode); > + struct xfs_mount *mp = ip->i_mount; > + int error = > + blk_status_to_errno(bio->bi_status); > + struct xfs_fsverity_ioend *fsv_ioend; > > if (!error && (ioend->io_flags & IOMAP_IOEND_INTEGRITY)) { > error = iomap_ioend_integrity_verify(ioend); > @@ -117,6 +138,36 @@ xfs_end_io_read( > } > } > > + /* > + * If we have fsverity and block device integrity attached to this bio, > + * we need to run fsverity verification of data folios from a separate > + * fsverity workqueue. This is necessary to avoid deadlocking due to > + * fsverity issuing more reads of fsverity metadata which would be > + * processed by the same worker in the BIO completion workqueue. > + * > + * Without block device integrity, fsverity metadata IO will not use > + * ioends for completion. > + */ > + if (IS_ENABLED(CONFIG_FS_VERITY) && !error && ioend->io_vi && > + xfs_fsverity_is_file_data(ip, ioend->io_offset)) { > + if (ioend->io_flags & IOMAP_IOEND_INTEGRITY) { > + fsv_ioend = kmem_cache_zalloc(xfs_fsverity_ioend_cache, > + GFP_KERNEL); > + if (!fsv_ioend) { > + iomap_finish_ioends(ioend, -ENOMEM); > + return; > + } > + fsv_ioend->ioend = ioend; > + INIT_WORK(&fsv_ioend->work, xfs_end_fsverity_io_read); > + > + fsverity_enqueue_verify_work(&fsv_ioend->work); > + return; > + } > + > + fsverity_verify_bio(ioend->io_vi, &ioend->io_bio); > + error = blk_status_to_errno(ioend->io_bio.bi_status); > + } > + > iomap_finish_ioends(ioend, error); > } > > @@ -125,13 +176,15 @@ xfs_ioend_submit_read( > struct inode *inode, > struct bio *bio, > loff_t file_offset, > - u16 ioend_flags) > + u16 ioend_flags, > + struct fsverity_info *vi) > { > struct xfs_inode *ip = XFS_I(inode); > struct xfs_mount *mp = ip->i_mount; > struct iomap_ioend *ioend; > > ioend = iomap_init_ioend(inode, bio, file_offset, ioend_flags); > + ioend->io_vi = vi; > if ((ioend_flags & IOMAP_IOEND_DIRECT) && > READ_ONCE(mp->m_read_bounce) == XFS_READ_BOUNCE_ALWAYS) { > iomap_bounce_read(ioend, bdev_logical_block_size(bio->bi_bdev), > diff --git a/fs/xfs/xfs_ioend.h b/fs/xfs/xfs_ioend.h > index 7c2a1ea3e6ed..992c248a693a 100644 > --- a/fs/xfs/xfs_ioend.h > +++ b/fs/xfs/xfs_ioend.h > @@ -2,6 +2,8 @@ > #ifndef __XFS_IOEND_H > #define __XFS_IOEND_H > > +#include > + > /* > * Fast and loose check if this write could update the on-disk inode size. > */ > @@ -13,6 +15,6 @@ static inline bool xfs_ioend_is_append(struct iomap_ioend *ioend) > > void xfs_end_bio(struct bio *bio); > void xfs_ioend_submit_read(struct inode *inode, struct bio *bio, > - loff_t file_offset, u16 ioend_flags); > + loff_t file_offset, u16 ioend_flags, struct fsverity_info *vi); > > #endif /* __XFS_IOEND_H */ > diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c > index fce1d2905c94..aca50130625e 100644 > --- a/fs/xfs/xfs_super.c > +++ b/fs/xfs/xfs_super.c > @@ -2516,8 +2516,20 @@ xfs_init_caches(void) > if (!xfs_parent_args_cache) > goto out_destroy_xmi_cache; > > +#ifdef CONFIG_FS_VERITY > + xfs_fsverity_ioend_cache = kmem_cache_create("xfs_fsverity_ioend", > + sizeof(struct xfs_fsverity_ioend), > + 0, 0, NULL); > + if (!xfs_fsverity_ioend_cache) > + goto out_destroy_fsverity_ioend_cache; > +#endif > + > return 0; > > +#ifdef CONFIG_FS_VERITY > + out_destroy_fsverity_ioend_cache: > + kmem_cache_destroy(xfs_fsverity_ioend_cache); > +#endif > out_destroy_xmi_cache: > kmem_cache_destroy(xfs_xmi_cache); > out_destroy_xmd_cache: > @@ -2580,6 +2592,9 @@ xfs_destroy_caches(void) > * destroy caches. > */ > rcu_barrier(); > +#ifdef CONFIG_FS_VERITY > + kmem_cache_destroy(xfs_fsverity_ioend_cache); > +#endif > kmem_cache_destroy(xfs_parent_args_cache); > kmem_cache_destroy(xfs_xmd_cache); > kmem_cache_destroy(xfs_xmi_cache); > -- > 2.54.0 > >